Hox genes

If regulatory genes can be likened to movie directors then the Homeobox genes (or Hox genes for short) are the Martin Scorsese of the gene world. They certainly get a lot of press and they may well be geniuses.

Hox genes encode transcription factors which switch on cascades of other genes, for instance all the ones needed to make a leg. This means that despite being fairly small (only 180 base pairs long in humans) they can have huge effects.

You can read about the discovery of Hox genes at the Howard Hughes Medical Institute and there are several interesting articles about Hox genes at the Pharyngula blog. Here's one on Hox genesis, and there's an overview of Hox genes here.

This time last year: The Thagomizer